Reducing gear



March 21, 1933.

G. PIRINOLI REDUC I NG GEAR Filed Sept. 23. 1931 was Mar. 21, 1933 umrso STATES PATENT OFFICE eoemnmo rmmon, or roam, many, assrnon 'ro new sooma mounts, on mam, nan! REDUCING G Application filed September 28, 1931, Serial 110. 564,650, and in Italy Kay 15, 1881.

This invention relates to a reducing gear of the sun and planet type for co-axial shafts rotating in opposite directions specially suitable for aircraft screw propellers arranged 3 on the same side with respect to the engine.

This reducing gear consists essentially in the combination of two reducing gears of the well-known sun and planet type, the planet wheels of the two gears being osi- 1 ti-vely connected together and having t fore common pivots. The mechanism parts are thus considerably reduced in number, size and weight with respect to two separate reducing gears, the construction being at the 1 same time simpler and stronger.

The acco'mpan ing drawin shows by way of example a re ucing gear or two co-axial aircraft propellers according to this invention.

0 The figure shows the reducing gear in axial section.

' The reducing ear is enclosed in an ogival box 1, attached y means of a flange to the engine casing 2 with the interpositlon of a diaphragm 3. The end of the engine shaft 4 passes through a suitable circular hole of the diaphragm 3 and carries the bevelled sun wheel 5 keyed thereto. The opposite rim 6 provided with a corresponding set of teeth is fixed to the casing 1 and constitutes a second sun wheel and the pinions 7 acting as planet P wheels mesh with'said wheels 5 and 6. The

pivot 8 of the pinions 7'-isfixed to the tubular shaft 9 on which the hub of the propeller 10 is keyed. Said shaft 9 is a part of adivided box 11, 12, provided with openings 11' 'for the pinions 7 and supporting the pivotS of said pinions. v

For the purpose of supporting the box 1112 its sleeve 13 is fitted on the hub of the toothed wheel 5' with the interposition of a bearing and is supported with the shaft 4 by the ball bearing 15 arranged in the diaphragm 3. Another ball bearing 16 at the ereopposite end of the box 1 supports the tubular shaft 9.

The above described mechanism constitutes a reducing gear of the sun and planet type between the engine shaft 4 and the driven shaft 9, said two shafts being co-axial to each other and rotating in the same direction. The drivin toothed wheel 5 causes the pinions 7 a to ri e on the fixed rim 6; the pinions 7 carry along their pivot 8 and therefore the box 1112 and the tubular shaft 9 integral with the box. The shaft 9 performs a number of turns which is one-half the number of turns of the shaft 4 in the same direction as the latter and carries along the propeller 10. According to this invention I incor porate with this propeller reducing-gear for the propeller 10 a second reducing gear for the pro Her 17 rotating in an o posite direction. he propeller 17 is ke e on the shaft 18 supported within the tub, ar shaft 9 by cylindrical bearings and the shaft 9 is supported b 'a ball bearing 16. The shaft 18 carries insi e the box 11-12 the bevel wheel 19 meshin the pinions 7 and rotating on the same pivots 8 carried b the box 11-12. It will be obvious that t e toothed wheel 19' i. e..the shaft 18 with the propeller 17, as well as the shaft 9 and its propeller 10 are capable, by the rovision of the mechanism accor to this invention, to rotate in difierent directions and at different speeds according to the position, diameter and number of teeth of the respec-' tive driving bevel wheels. Spur instead'of bevel wheels can be employe in the mechanism according to this invention and other members can be modified without departingfrom the spirit of my invention. What I claim is: In a reducing gear, the combination wit a casing, a drlvmg shaft and two driven shafts concentrically to each other and in alignment with-the driving shaft,- of K with the pinions 20 integral with 7 2 I on s- 24 a sun gear fixed to the casing, a sun gear keyed to said driving shaft, planet gears comprising two toothed rims, one of which meshes simultaneously with both of said sun gears, a casing for said planet gears con-.

nected with the outer driven shaft and supported on both sides by the first-mentioned casing said casing being provided with openings, t rough WhlCh project the toothed runs meshing wlth the fixed sun gears and a third sun gear keyed on the inner driven shaft and meshing with the other toothed rim of said planet gears.

In testimony whereof, I hereunto aflix my signature.

I GUGLIELMO PLRINOLI. 

